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When I add aerial images from a recent survey (delivered in EPSG:31468, DHDN_3_Degree_Gauss_Zone_4) to a map document, these differ in position from a basemap as can be seen in the screenshot below (about 150m in ~40°). I carried out these steps:

  • Set up a new map document
  • Set data frame coordinate system to EPSG:31468
  • add the aerial image
  • add a basemap (here: openstreetmap)

Overlaying it with a parcel dataset from a different source indicates that my aerial image is positioned correctly, so what have I done wrong?

Aerial vs. osm basemap:

enter image description here

Overlay with parcel dataset:

enter image description here

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    It looks like you have not set a transformation between the datum of your aerial images and the datum of your basemap. support.esri.com/technical-article/000002828
    – PolyGeo ♦
    Commented Jul 4, 2016 at 9:08
  • Convert from GCS_Deutsches_Hauptdreiecksnetz into GCS_WGS_1984 (must be added explicitly) and selecting one of the procections (DHDN_To_WGS_1984_4_NTv2) solved my issue.
    – Jochen Schwarze
    Commented Jul 4, 2016 at 9:35
  • I think it would be worth you adding that, plus the link I provided as an answer.
    – PolyGeo ♦
    Commented Jul 4, 2016 at 10:27

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As determined by PolyGeo this is a transformation issue (http://support.esri.com/technical-article/000002828). Steps to solve this in detail:

Right click Layers, chose properties, 'Coordinate System' tab:

enter image description here

Click 'Transformations...'

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Note that at this point no transformation method can be selected.

Under 'Convert from:' select GCS_WGS_1984 and 'Into:' GCS_Deutsches_Hauptdreiecksnetz (applies for this example):

enter image description here

Now a transformation method can be selected:

enter image description here

Click OK. Now the basemap layer matches the aerial image:

enter image description here

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